Conduits are often laid underground in covered trenches for long distances. Subsequently, fiber-optic cables or the like are installed in these conduits. During installation the cables are propelled from the open installation end of the conduit over a distance to the open exit end of the length of conduit by a combination of mechanical feeding and air pressurization as illustrated in U.S. Pat. No. 6,059,264 by Kaminski, et al.
The leading end of the cable is affixed with a device that allows free movement of the device through the conduit while also providing a seal between the device and the inside diameter of the conduit. This device is often referred to as a “bird”, “parachute”, or projectile, or the like. When the open installation end of the conduit is pressurized the pressure differential across the bird propels the bird and the attached cable along the path of the conduit to the open exit end of the conduit. The bird and attached cable may arrive at this exit end at very high velocity. Bodily injury, such as broken limbs, and, property damage, such as firing the projectile and cable over external power lines, have been reported as a result of the violent exit of the bird and cable from the exit end of the conduit.
U.S. Pat. No. 6,318,411 by Kology addresses these problems by using a receiver at the exit end of a conduit to absorb energy and catch the bird. This prior art describes the proofing of a conduit using only a bird, such as, if the bird can be sent through the conduit and arrive at the exit end, the conduit is assumed to be free of obstruction, and hence, ready for cable installation. Kology describes a three-piece tubular structure with a removable cap, which contains an energy absorbing rubber stop. One section of the tubular structure contains attachment threads for joining the removable cap. The second section contains perforations for allowing air escapement that accumulates in front of the moving bird. The third section is a transition tube that adapts the second section diameter to the conduit by reducing the third section diameter so that the inside diameter of the third section equals the inside diameter of the conduit.
The prior art requires a different size receiver for each different size of conduit. Separate conduit clamps or couplers must be provided to attach the receiver to the conduit.